163 Erigone

163 Erigone is an asteroid from the asteroid belt and the namesake of the Erigone family of asteroids that share similar orbital elements and properties. It was discovered by French astronomer Henri Joseph Perrotin on April 26, 1876, and named after one of the two Erigones in Greek mythology. This asteroid is orbiting the Sun at a distance of 2.37 AU with a period of 3.643 years and an eccentricity (ovalness) of 0.19. The orbital plane is inclined at an angle of 4.8° to the plane of the ecliptic.^[3]

163 Erigone

3D convex shape model of 163 Erigone
Discovery
Discovered by	J. Perrotin
Discovery site	Toulouse
Discovery date	26 April 1876
Designations
MPC designation	(163) Erigone
Pronunciation	/ɪˈrɪɡəniː/[1]
Named after	Erigone
Alternative designations	A876 HC; 1892 RA; 1957 OT; 2017 YH23
Minor planet category	Main belt (Erigone)
Adjectives	Erigonian /ɛrɪˈɡoʊniən/[2] Erigonean /ɛrɪɡəˈniːən/
Orbital characteristics[3]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	123.56 yr (45131 d)
Aphelion	2.8188 AU (421.69 Gm)
Perihelion	1.9161 AU (286.64 Gm)
Semi-major axis	2.3675 AU (354.17 Gm)
Eccentricity	0.19064
Orbital period (sidereal)	3.64 yr (1330.5 d)
Mean anomaly	280.031°
Mean motion	0° 16m 14.052s / day
Inclination	4.8148°
Longitude of ascending node	160.166°
Argument of perihelion	298.260°
Earth MOID	0.93686 AU (140.152 Gm)
Jupiter MOID	2.3628 AU (353.47 Gm)
TJupiter	3.518
Physical characteristics
Dimensions	72.63±5.7 km[3] 72.70 ± 1.95 km[4]
Mass	(2.01 ± 0.68) × 1018 kg[4]
Mean density	9.99 ± 3.45 g/cm3[4]
Synodic rotation period	16.136 h (0.6723 d)[5]
Geometric albedo	0.0546±0.010[3] 0.0428 ± 0.0092 [6]
Spectral type	C[6] (Tholen)
Absolute magnitude (H)	9.47,[3] 9.48[6]

Photometric measurements taken in 2014 were used to construct a lightcurve that demonstrated a rotation period of 16.136±0.001 h with an amplitude of 0.32±0.02 in magnitude.^[5] Erigone is a relatively large and dark asteroid with an estimated size of 73 km.^[4] Based upon its spectrum, it is classified as a C-type asteroid,^[6] which indicates that it probably has a carbonaceous composition. It is the largest member of the eponymously named Erigone collisional family.^[7]

2014 occultation of Regulus

Path of occultation from New York to Ontario

In the early morning hours of March 20, 2014, Erigone occulted the first-magnitude star Regulus,^[8] as first predicted by Aldo Vitagliano in 2004 using the SOLEX software.^[9] This would have been a rare case of an occultation of a very bright star visible from a highly populated area, since the shadow path moved across New York state and Ontario, including all five boroughs of New York City.^[9] Observers in the shadow path would have seen the star wink out for as long as 14 seconds.^[8][10]

However, thick clouds and rain blocked the view for most if not all people on the shadow path.^[11] The website of the International Occultation Timing Association does not list any successful observations at all.^[12]

Two single chord Asteroid Occultation events have been observed, in 2013 and 2015.^[13]

References

1. Noah Webster (1884) A Practical Dictionary of the English Language
2. Publius Ovidius Naso, John Gower (1640) Ovids Festivalls
3. "163 Erigone". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 12 May 2016.
4. Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73 (1): 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
5. Pilcher, Frederick; et al. (July 2014). "Rotation Period Determination for 163 Erigone". Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers. 41 (3): 187. Bibcode:2014MPBu...41..187P.
6. Pravec, P.; et al. (May 2012), "Absolute Magnitudes of Asteroids and a Revision of Asteroid Albedo Estimates from WISE Thermal Observations", Asteroids, Comets, Meteors 2012, Proceedings of the conference held May 16–20, 2012 in Niigata, Japan, vol. 1667, no. 1667, p. 6089, Bibcode:2012LPICo1667.6089P. See Table 4.
7. Morate, David; et al. (February 2016), "Compositional study of asteroids in the Erigone collisional family using visible spectroscopy at the 10.4 m GTC", Astronomy and Astrophysics, 586: 18, arXiv:1701.03761, Bibcode:2016A&A...586A.129M, doi:10.1051/0004-6361/201527453, A129.
8. Dunham, David (2006). "The International Occultation Timing Association 24th Annual Meeting at Mt. Cuba Observatory, Greenville, Delaware". International Occultation Timing Association. Archived from the original on 18 July 2011. Retrieved 13 February 2011.
9. Vitagliano, Aldo (2010). "The Solex Page". Università degli Studi di Napoli Federico II. Archived from the original on 20 December 2008. Retrieved 13 February 2011.
10. Preston, Steve (14 March 2014). "(163) Erigone / HIP 49669". Asteroid Occultation. Archived from the original on 24 December 2013. Retrieved 14 March 2014.
11. Asteroid eclipse rained out Space.com 2014 March 20
12. Regulus 2014 Archived 21 November 2020 at the Wayback Machine International Occultation Timing Association
13. "PDS Asteroid/Dust Subnode". sbn.psi.edu. Archived from the original on 25 April 2018. Retrieved 25 April 2018.

External links

• 163 Erigone at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 163 Erigone at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters